Arsenic Removal with Bayoxide® E33 Ferric Oxide …nysawwa.org/docs/pdfs/7B - Drinking Water is no...

Arsenic Removal withBayoxide® E33 Ferric Oxide Media

& SORB 33® As Adsorption

Frank StanishSevern Trent Services, Inc.

AWWA New York ConferenceSaratoga Springs, NY

April 15, 2015

Severn Trent Services 2

Agenda

Background on arsenic Arsenic Toxicity Sources of arsenic Arsenic in Water Arsenic Regulations Arsenic Treatment Methods Case Study Problem and Solution:

Hilltown Township Arsenic Removal Project

Frequently Asked Questions


Arsenic Background

Natural occurring metalloid element Atomic Symbol: As Atomic number: 33 Atomic Weight: 74.92

Arsenic Toxicity


USEPA Group A Human Carcinogen Short-term (acute) and long-term (chronic) effects Skin, lung and bladder cancer Acute GI damage Cardiac problems Vomiting / Diarrhea Dehydration Partial paralysis / blindness Hemolysis Vertigo Shock / Death


Arsenic Chemistry

“Oxidized” As(V) Oxyanion DissociationH3AsO4 H2AsO4

- + H+ pKs = 2.2

H2AsO4- HAsO4

2- + H+ pKs = 6.9

HAsO42- AsO4

3- + H+ pKs = 11.5

“Reduced” As(III) Oxyanion DissociationH3AsO3 H2AsO3

- + H+ pH 6 - 8

In waters within a natural pH range, the following species are present:

H3AsO3, H2AsO3-, H2AsO4

- & HAsO42-

As(III) occurs mainly under reducing conditions, e.g., in the absence of oxygen.When this water comes in contact with air, As(III) is oxidized to As(V).

Arsenic found in ground waters is normally in an inorganic form as a soluble oxyanion species. It has 2 valence states, As(III) and As(V).

Arsenic Sources in US Drinking Water



USEPA Arsenic Rule & Severn Trent’s Role

Timeline - Lower Potable Water Arsenic LevelsCurrent Limit in 1990’s - 50 g/L1993 WHO Recommends 10 g/L1994 USEPA Recommends 2-20 g/L2000 New EC Directive 2003 UK Adopts 10 g/L Standard2006 USEPA Compliance for 10 g/L MCL

Severn Trent WaterSevern Trent Services’ Sister Company in the UK16 Well Water Sites with As > 10 g/LTotal Treatment Capacity - 46.8 MGD (177 ML/Day) since 2003


As Removal – Treatment Selection

Adsorption Simple & non-regenerative in most cases Single step process for most applications

Coagulation/Filtration Cost effective for large scale systems (over 4 MGD) Effective for high Fe/Mn waters No chemicals besides disinfection if Fe/As wgt ratio > 25

Reverse Osmosis Effective if other TDS must be removed Won’t remove As(III)

Ion Exchange Good for waters with high As & pH and low SO4 & HCO3

Hybrid resins with impregnated Fe Oxide – Selective for As Requires regeneration/postreatment; won’t remove As(III)


SORB 33® Adsorption with Bayoxide® E33 Media

SORB 33® - Severn Trent’s Adsorption Process STS & Lanxess Partnered to Develop Granular Ferric Oxide

(GFO) Media for As Removal Lanxess: Large Technical Oxide Producer Specialists in Iron Oxide Technologies Bayoxide® E33 (GFO) - Adsorption Media Exclusive Agreement between STS & Lanxess NSF Standard 61 Approved


Adsorption - SORB 33® Systems

Water Flows through a bed of media Pros

Easy Operation Little automation Simple Maintenance Not complex Lowest Capital Commonly lowest O&M

Cons Complex Waters with multi

contaminants Causes low bed volumes

Most accepted technology Majority of projects in US have

selected adsorption


Adsorption - SORB 33® Systems

Loma Linda, CAFour 14’-Ø Adsorbers

3,000 gpm

Bernallilo, NMFour 4’-Ø Adsorbers

450 gpm

Adsorptive Media Pilot Testing – 3rd Party Breakthrough Curves – determine best performance 4 different medias tested at Mesa, AZ by DSWA


B ed V olum e vs. A rsen ic

0

5

10

15

20

25

30

35

0 10,000 20,000 30 ,000 40,000 50,000 60 ,000

B ed V olu m es

Ars

enic

, ppb

A verage InfluentW R T Z33G FHSolm etex A sX npB ayox ide E 33


Test Evaluation – Breakthrough Curves

0

10

20

30

40

0 25,000 50,000 75,000 100,000 125,000 150,000

Con

cent

ratio

n (μ

g/L)

Bed Volumes of Water Treated (BV’s)

Typical SORB 33® Arsenic Adsorption Curve

TreatedWater As

Influent As

As MCL As Breakthrough

6 Mos 12 Mos 18 MosTime (based on 75% Use Factor):

0

10

20

30

40

0 25,000 50,000 75,000 100,000 125,000 150,000

Con

cent

ratio

n (μ

g/L)

Bed Volumes of Water Treated (BV’s)

Typical SORB 33® Arsenic Adsorption Curve

TreatedWater As

Influent As

As MCL As Breakthrough

6 Mos 12 Mos 18 MosTime (based on 75% Use Factor):

Breakthrough Curve Measures Media Performance - Longevity Arsenic effluent levels vs volume treated (“BV’s” or gallons H2O/cu ft of media) As Breakthrough – Point at which media needs replacement The higher the BV’s to breakthrough, the lower the operating cost


On-site Pilot Test Program

MediaDrain

VentV-11

B’wash Discharge

PDI

Efflu

ent/M

edia

Bac

kwas

hMedia

Support

BackwashSample

Treated WaterSample/Drain

E33 FeedSample

P-01

P-04

P-02

S-06

S-08

S-07

E33GFO

Media

PG

P-09

TreatedWater

OrBackwashEffluent

B’wash Supply

FQI FI

Pres

Reg

’rR

ate

Set

WellWater

P-01

P-03

FI/FQI

P-04

P-02

Rate Set

P-03

MediaDrain

VentV-11

B’wash Discharge

PDI

Efflu

ent/M

edia

Bac

kwas

hMedia

Support

BackwashSample


E33 FeedSample

P-01

P-04

P-02

S-06

S-08

S-07

E33GFO

Media

PG

P-09

TreatedWater

OrBackwashEffluent

B’wash Supply

FQI FI

Pres

Reg

’rR

ate

Set

WellWater

P-01

P-03

FI/FQI

P-04

P-02

Rate Set

P-03

MediaDrain

VentV-11

B’wash Discharge

PDI

Efflu

ent/M

edia

Bac

kwas

hMedia

Support

BackwashSample


E33 FeedSample

P-01

P-04

P-02

S-06

S-08

S-07

E33GFO

Media

E33GFO

Media

PG

P-09

TreatedWater

OrBackwashEffluent

B’wash Supply

FQI FI

Pres

Reg

’rPr

es R

eg’r

Rat

e Se

tR

ate

Set

WellWater

P-01

P-03

FI/FQI

P-04

P-02

Rate Set

P-03

Program Scope

Test Protocol

4”- Clear Column with Media

Manual Valves

Simple Instruments

Consistent Water Supply

Data Collection & Monitor

Weekly Sampling

2-6 Month Program


Coagulation / Filtration - Omni-SORB™ Media Product Composition

5% Manganese Dioxide (MnO2) impregnated quartz (sand)

Non-porous blackish gray “catalytic” filtration media

Dense media – 88 lb/ft3

Screen Size – 18 x 60 mesh Dustless – facilitates backwash

Producer Fermavi (Brazil) – Mines rich MnO2 ore, refines into product

Media Life – 9+ Years; Disposable as nonhazardous waste

Service Conditions Filtration rates of 7-10 gpm/ft2

Backwash rates of 14-16 gpm/ft2


Coagulation / Filtration Iron Removal

Removes Fe and Mn Removal As/Fe/Mn

Needs high Iron level Fe:As - 25:1 or better

As/Fe/Mn or Fe/Mn Catalyze the Fe and Mn in

an oxidation/precipitation process

Coagulation / Filtration of Fe oxide & Mn oxide

Ferric chloride addition if needed

As adsorbed by Fe oxide Backwash

Coagulation / Filtration - Omni-SORB™ Media


Omni-SORB Systems Parallel Flow Filters Automated Valves Process Controls & PLC

Rozel, KS – 600 gpmFe & Mn RemovalThree 6’-Ø Filters

Houghton, NY – 700 gpmAs Coag FiltrationFour 7’-Ø FiltersN+1 Redundancy


Application Inquiry toFull Scale System …Step 1

Site Qualification Form Complete & Submit Client & Contact Info Flows, contaminants &

concentrationsSevern Trent Analysis Conceptualize

Design Flexibility

Budget Proposal Budget Capital Budget O&M

Water Quality


Characterization Key to Design Site Qualify Form’s analytical table highlights key species

Key Species Arsenic (As, g/L) – Bypass if As <25; Series if As >25 pH (no units) – Use CO2 or Acid to adjust if water pH >8.0 and/or high

SiO2

Phosphate (PO4 or P mg/L) – Consumes media capacity; Use Omni-SORB if PO4 > 0.8 (0.3 mg/L as P)

Silica (SiO2, mg/L) – Coats media above 40; use pH adjust Iron (Fe, mg/L) – If Fe >0.2, As is reduced; chlorination required; If Fe

>0.35, consider Omni-SORB Manganese (Mn, mg/L) – If Mn >0.06, Mn buildup in bed, makes

backwash difficult; chlorination required; Omni-SORB pretreat Vanadium (V, g/L) – Consumes media capacity; pH adjust helps

reduce its effect


Sizing & EstimateSummary …Adsorption Example

Process Sizes System Vessel Size Media Volume Performance – BV’s, etc. Flows Configuration Operating Costs: Includes

annualized media replace & chemicals

Proposals Estimates Cost ROM or Budget

Rough Order of Magnitude Issue to Client


Media Replacement & DisposalMedia Removal STS subcontractors Vacuum removal or

vactor truck Fill rolloffs or sacks TCLP analysis – verify

media is non-hazardousMedia Replacement Gravity fill - 52 ft3 sacks Hydraulic fill -

eductors

Aqua Pennsylvania SiteRoof Hatch Added for Gravity Fill30 Minute Fill - 52 ft³ per Vessel

Roof Hatch Added

Case Study – Hilltown Township, PA


Hilltown Township Well No. 2Hybrid Fe/Mn Filtration & As Adsorption

Well No. 3 – 300 gpm Multiple Contaminants

Arsenic – 15 µg/L Iron – 250 µg/L Manganese – 110 µg/L

Aside from As removal, needed to remove Fe & Mn Black & red water issue

Hybrid design – 1 OmniSORB filter & 2 E33 Adsorbers Oxidize & filter all of the water to remove Fe & Mn Treat 50% of filtered water through adsorption Bypass and blend remainder

System in service for 9 years Bayoxide E33 lasted 7 years before replacement Severn Trent Services 23

Hilltown TownshipHybrid Fe/Mn Filtration & As Adsorption


www.severntrentservices.com

Severn Trent Water Purification, Inc.Gary M. Lohse, P.E. – Regional Sales Manager3000 Advance LaneColmar, PA 18915

T: +1 215 859-3814E: [email protected]

Questions?Acknowledgements:

Gary Weaver - PrincipalCastle Valley Consultants, Inc.10 Beulah Road215 348 [email protected]

Arsenic Removal with Bayoxide® E33 Ferric Oxide …nysawwa.org/docs/pdfs/7B - Drinking Water is no...

Documents

Transcript of Arsenic Removal with Bayoxide® E33 Ferric Oxide …nysawwa.org/docs/pdfs/7B - Drinking Water is no...